The present invention relates to dispensing apparatus.
Dispensing apparatus of a kind for dispensing a fluid (usually a viscous liquid, whether in the form of a paste or otherwise) is well known for applying therapeutic substances into animals or onto animals. Such dispensing apparatus also have applications elsewhere, e.g.; for dispensing predetermined amounts of a material into, for example, a pot or the like for growing plants.
Dispensing apparatus of the present invention is preferably of a kind adapted for oral drenching or pour-on application of an animal remedy and/or supplement. Examples include parasiticides such as anthelmintics.
Whilst discharging of such fluids has been common from cartridges it is more usual for such liquid or liquid carried materials to be supplied via a conduit from a tank or pouch pack into a dispensing gun type apparatus. In the preferred form of the present invention that is the form of dispensing apparatus to which the present invention is directed. Accordingly, references to an xe2x80x9coutletxe2x80x9d should be taken to include within its scope any downstream device to assist (whether with or without the use of additional valving) the application of the fluid to a desired animal location.
There is sometimes a desire to be able to control the level of dose. The present invention relates to such apparatus having a capability of allowing a chosen dose within a range of doses. Devices of this kind have hitherto been known.
One such dose adjustment mechanism involves a rotational adjustor. Such a form of dispensing apparatus is disclosed in New Zealand Patent Specification No. 191016 of N J Phillips Pty. Limited and the full content thereof is hereby here included by way of reference.
Another form of such apparatus is that disclosed in New Zealand Patent Specification No. 222692 of Instrument Supplies Limited. It disclosed the use of a rotatable adjustor which carries a semi-circular wall having at each end of the wall edges that extend mutually parallel from the rotatable knob which provides the wall base. Such a wall between the first and second edges has its free periphery stepped so as to act on a fixed abutment member in the drench gun, the step aligned determining the axial extent of piston movement with the stepped semi-circular wall.
The present invention is directed to an alternative to such prior art devices.
As used herein xe2x80x9cliquidxe2x80x9d covers solutions, suspensions, emulsions, suspo-emulsions, gels, etc. capable of being piston expressed from an outlet.
In a first aspect the present invention consists in dispensing apparatus of a kind having a barrel with an inlet and an outlet and an operator actuable piston reciprocally movable in said barrel,
wherein said piston, in use, when moving away from said outlet, allows a liquid to enter space between said piston and said outlet,
and wherein subsequent movement (xe2x80x9cdischarging movementxe2x80x9d) of said piston, in use, towards said outlet causes liquid to exit said outlet,
and wherein the stroke of said discharging movement is controlled by a stop mechanism for the piston, said stop mechanism comprising including spiral staircase means through which liquid can pass and a staircase step abutment member carried by the piston or an assembly which includes the piston can butt at the limit of said discharging movement on a step of said spiral staircase means, said abutment member being rotatable about both the barrel and spiral staircase axes by externally accessible means to determine a stroke limiting choice of step in the staircase to encounter the abutment member and thus the quantity of liquid to be dispensed by a single discharging movement of said piston.
In another aspect the present invention consists in liquid dispensing apparatus having hand actuable means to move a piston against biassing means so as to discharge at least part of the liquid content from a barrel, said barrel having fixed relative thereto a helical abutment structure and wherein said piston forms part of an assembly which allows an uptake of liquid into said barrel during retraction under the action of said biassing means and wherein the limit of the liquid discharging step from that retracted piston condition is determined by the selection of that part of the helical abutment feature to be encountered during the dispensing stroke.
Preferably said helical abutment feature is a staircase. In other forms it can be a continuous surface.
Preferably one or more of the barrel, piston and helical abutment structure is detachable from the other components of the apparatus.
In another aspect the present invention consists in, in a drench gun (whether for pour-on or oral drenching purposes or for any other purpose) of a kind capable of being actuated to cause a piston to reciprocate within a dispensing channel, there being one way valve means to allow an uptake of liquid to be dispensed into the dispensing side of the piston in the barrel, a stroke adjustment mechanism comprising or including
an abutment member carried by the piston assembly capable of being rotated about the piston axis by means of an adjustment accessible to an operator (such adjustment preferably being possible by hand with reference to a scale indicating the quantity to be dispensed) and
a helical abutment feature (stepped or continuous or otherwise) adapted to provide an abutment for said rotatable abutment member thereby to adjust the allowed extent of travel of the piston during a dispensing motion owing to the end of travel occurrence of an abutment between the piston carried abutment feature and the helical abutment feature.
Preferably said helical abutment feature is a moulded element (preferably in the form of a spiral staircase or the like member) that is integral with or which is fixed in a fabricated structure relative to the barrel or that part of the barrel to be a sleeve for the piston.
Preferably said helical abutment feature is or defines a spiral staircase.
Preferably the said piston includes an axial conduit controlled by said one way valve means.
Preferably said piston is biassed to a retracted condition.
Preferably said piston is biassed by means included in the handle structure.
Preferably said handle is squeezed against the bias of said biassing means to cause a liquid dispensing stroke of said piston is capable of being squeezed to confer a withdrawing bias to the assembly.
Preferably said drench gun is disassemblable to enable removal of a barrel, a piston and/or a helical abutment feature.
Preferably said drench gun is capable of reassembly after disassembly with the same or a different barrel, piston and/or helical abutment feature.
In a further aspect the present invention consists in an apparatus for dispensing a selected volume of a liquid, said apparatus comprising or including:
a handle assembly of pivotally interconnected first and second handle components and means to bias such handle components apart about the pivot, one of said components (xe2x80x9cthe first componentxe2x80x9d) at a region distal from said pivot having a sleeve form, the axis of which sleeve form is normal to said pivot axis,
a piston assembly linked from the second handle component at or from a region distal thereof from said pivot, such piston assembly extending through said sleeve, said piston assembly connecting said second component to the piston and providing or defining a conduit for the receiving and conveying liquid to be dispensed via a one way valve out of said piston,
a member or assembly (thereafter xe2x80x9cabutment defining memberxe2x80x9d) located on or about said piston assembly and rotatable about the stroke axis thereof by manual actuation externally of said sleeve,
an escarpment member located at least in part in said sleeve and providing an escarpment of steps on each of at least several of which part of said abutment defining member can abut to limit the discharge stroke of said piston assembly upon a manual squeezing of the handle components together about the pivot, and
a barrel member about the piston adjacent to and/or indexed to the sleeve of said first component and/or said escarpment member and held in a fixed relationship with both the sleeve and the escarpment member, said barrel member having an outlet, a one way valved outlet or extending to a one way valved outlet assembly,
wherein, reliant on the one way of valve of said piston assembly, liquid can enter said barrel between said piston and outlet at least as said second handled component retracts under the action of said means to bias and thereafter the piston can drive liquid from the barrel to the extent allowed by the discharge stroke limit of the piston in the barrel as the handle components are squeezed against the bias, such stroke limit being determined by the particular alignment of the abutment defining member with a particular step of the escarpment member.
Preferably said barrel member is held in said fixed relationship with the sleeve and escarpment member by a screw engaged collar engaged to said sleeve.
Preferably said barrel member indexes to said escarpment member by a male/female inter-engagement.
Preferably said escarpment member is in the form of a spiral staircase formed as part of a moulded member having an outwardly extending flange to butt on one end of said sleeve of said first component and an inwardly extending flange having openings each to receive a projection of said barrel in said male/female indexing manner.
In still a further aspect the present invention consists in an apparatus for dispensing a selected volume of a liquid, said apparatus comprising or including
a handle assembly of first and second handle components inter-related sufficiently to ensure the prospect of reproducible movement towards or away from each other,
an assembly supported on one of said handle components (xe2x80x9cthe first componentxe2x80x9d) which comprises or includes
an escarpment member which defines a spiral staircase that faces back towards the second handle component and
a barrel coaxially aligned with said escarpment member, said barrel having or extending to an outlet, and
an assembly including or comprising a conduit capable of being connected to a source of liquid supply which assembly extends from said second handle component into said barrel where it carries a piston, there being a one way valve in the conduit and/or piston to enable liquid entry upon retraction of the piston,
and wherein the conduit carries there around an abutment member associated with an external rotational control which can be aligned with a desired step of the escarpment member spiral staircase so as to be determinate of the dispensing stroke limit of the piston.
In a further aspect the present invention consists in an apparatus for dispensing a selected volume of a liquid, said apparatus comprising or including:
a handle assembly of pivotally interconnected first and second handle components and means to bias such handle components apart about the pivot, one of said components (xe2x80x9cthe first componentxe2x80x9d) at a region distal from said pivot having a sleeve form, the axis of which sleeve form is normal to said pivot axis;
a piston assembly linked from the second handle component at or from a region distal thereof from said pivot, such piston assembly extending through said sleeve, said piston assembly connecting said second component to an interchangeable piston and providing or defining a conduit for the receiving and conveying liquid to be dispensed via a one way valve out of said piston;
a member or assembly (thereafter xe2x80x9cabutment defining memberxe2x80x9d) located on or about said piston assembly and rotatable about the stroke axis thereof by manual actuation externally of said sleeve;
an interchangeable escarpment member located at least in part in said sleeve and providing an escarpment of steps on each of at least of several of which part of said abutment defining member can abut to limit the discharge stroke of said piston assembly upon a manual squeezing of the handle components together about the pivot; and
an interchangeable barrel member about the piston adjacent to and/or indexed to the sleeve of said first component and/or said escarpment member and held in a fixed relationship with both the sleeve and the escarpment member, said barrel member having an outlet, a one way valved outlet or extending to a one way valved outlet assembly;
wherein, reliant on the one way of valve of said piston assembly, liquid can enter said barrel between said piston and outlet at least as said second handled component retracts under the action of said means to bias and thereafter the piston can drive liquid from the barrel to the extent allowed by the discharge stroke limit of the piston in the barrel as the handle components are squeezed against the bias, such stroke limit being determined by the particular alignment of the abutment defining member with a particular step of the escarpment member,
and wherein interchange of at least one of the interchangeable members can vary the range of volumes capable of being dispensed.
Preferably both the piston and its barrel is interchangeable.
In a further aspect the present inventions consists in an apparatus for dispensing a selected volume of a liquid, said apparatus comprising or including
a handle assembly of first and second handle components inter-related sufficiently to ensure the prospect of reproducible movement towards or away from each other;
an assembly supported by one of said handle components (xe2x80x9cthe first componentxe2x80x9d) which includes an interchangeable barrel having or extending to an outlet; and
an assembly including or comprising a conduit capable of being connected to a source of liquid supply which assembly extends from said second handle component into said barrel where it carries an interchangeable piston appropriate for the barrel selected, there being a one way valve in the conduit and/or piston to enable liquid entry upon retraction of the piston; and
an interacting arrangement of an abutment member and an escarpment member capable of being interactive to limit a stroke of said piston in said barrel, yet by rotation of the members relative to each other can vary that stroke;
and wherein volume can in addition be varied by at least one of
(a) barrel interchange,
(b) piston interchange,
(c) escarpment member interchange, and
(d) abutment member interchange.
Preferably in use, said apparatus can dispense incrementally over a fist range and, after reassembly with associated components, can dispense incrementally over a second range not coextensive with said first range.
In another aspect the present invention consists in (I) apparatus for dispensing a selected volume of a liquid, said apparatus comprising or including:
a handle assembly of pivotally interconnected first and second handle components and means to bias such handle components apart about the pivot, one of said components (xe2x80x9cthe first componentxe2x80x9d) at a region distal from said pivot having a sleeve form, the axis of which sleeve form is normal to said pivot axis;
a piston assembly linked from the second handle component at or from a region distal thereof from said pivot, such piston assembly extending through said sleeve, said piston assembly connecting said second component to an interchangeable piston and providing or defining a conduit for the receiving and conveying of liquid to be dispensed via a one way valve out of said piston;
a member or assembly (thereafter xe2x80x9cabutment defining memberxe2x80x9d) located on or about said piston assembly and rotatable about the stroke axis thereof by manual actuation externally of said sleeve;
an interchangeable escarpment member located at least in part in said sleeve and providing an escarpment of steps on each of at least of several of which part of said abutment defining member can abut to limit the discharge stroke of said piston assembly upon a manual squeezing of the handle components together about the pivot; and
an interchangeable barrel member about the piston adjacent to and/or indexed to the sleeve of said first component and/or said escarpment member and held in a fixed relationship with both the sleeve and the escarpment member, said barrel member having an outlet, a one way valved outlet or extending to a one way valved outlet assembly;
wherein, reliant on the one way valve of said piston assembly, liquid can enter said barrel between said piston and outlet at least as said second handled component retracts under the action of said means to bias and thereafter the piston can drive liquid from the barrel to the extent allowed by the discharge stroke limit of the piston in the barrel as the handle components are squeezed against the bias, such stroke limit being determined by the particular alignment of the abutment defining member with a particular step of the escarpment member,
and wherein interchange of at least one of the interchangeable members can vary the range of volumes capable of being dispensed, and
(II) at least one or more of said interchangeable members the use of which in the apparatus will lead to a dosage range not coextensive with the dosage range of the apparatus in its initial form or when assembled as in (I).
In another aspect the present invention consists in (I) apparatus for dispensing a selected volume of a liquid, said apparatus comprising or including
a handle assembly of first and second handle components inter-related sufficiently to ensure the prospect of reproducible movement towards or away from each other;
an assembly supported by one of said handle components (xe2x80x9cthe first componentxe2x80x9d) which includes an interchangeable barrel having or extending to an outlet; and
an assembly including or comprising a conduit capable of being connected to a source of liquid supply which assembly extends from said second handle component into said barrel where it carries an interchangeable piston appropriate for the barrel selected, there being a one way valve in the conduit and/or piston to enable liquid entry upon retraction of the piston; and
an interacting arrangement of an abutment member and an escarpment member capable of being interactive to limit a stroke of said piston in said barrel, yet by rotation of the members relative to each other can vary that stroke;
and wherein volume can in addition be varied by at least one of
(a) barrel interchange,
(b) piston interchange,
(c) escarpment member interchange, and
(d) abutment member interchange, and
(II) at least one or more additional components to allow (a), (b), (c) and/or (d).
In a further aspect the present invention consists in a method of varying the range of incremental dosages capable of being dispensed from a dispensing apparatus which comprises taking a combination as previously defined and varying the discharge volume allowed for a particular stroke limit by component interchange.
In a further aspect the present invention consists in a method of dispensing a range of selected dosages within a range or within ranges which involved the operative use of the apparatus as herein described.
Preferably the apparatus is as herein described where any one or more of any component is substantially hereinafter described with reference to any one or more of the accompanying drawings.
Preferably the method of dispensing a liquid over increments in one or more ranges is performed substantially herein described with reference to any one or more of the accompanying drawings.
Preferably the arrangement is substantially as hereinafter described with reference to any of the accompanying drawings.
In another aspect the invention consists in the use of the apparatus as herein described.
As used herein reference to xe2x80x9chelicalxe2x80x9d includes any similar such arrangement which presents some degree of spiral arrangement continuous or discontinuous, ie; it could be castellations carried internally of a member each distinct from the other but sufficiently spaced in conjunction with the action of the piston carried abutment member to achieve the desired end. Also whilst reference is made herein to the helical abutment feature being about the axis of the barrel and/or piston, persons skilled in the art will appreciate how, if desired, it can be some offsetting from that axis while still achieving the end of providing a readily moveable and scale referenced adjustment whereby there can be control of the discharging quantity.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.